nir: add a pass to compact clip/cull distances.

v2: Use nir_is_per_vertex_io() rather than is_arrays_of_arrays().

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/compiler/nir/nir.h

@@ -2441,6 +2441,7 @@ bool nir_lower_idiv(nir_shader *shader);
 
 void nir_lower_clip_vs(nir_shader *shader, unsigned ucp_enables);
 void nir_lower_clip_fs(nir_shader *shader, unsigned ucp_enables);
+void nir_lower_clip_cull_distance_arrays(nir_shader *nir);
 
 void nir_lower_two_sided_color(nir_shader *shader);